Moved my rig into new case with modified w/c setup and now realised that my trusty Corsair HX620 is really doing well.
Case is modified V2000 with PA120.2 and 4 nexus fans. Runs another 3 of these elsewhere as well as
Q6600 @ 3.6 and Laing DDC pump
6GB RAM
MSI 7900GTO (512MB o/c past GTX)
Gigabyte P35-DS4 with 6 hard drives on the Intel SATA Controller and 2 Optical drives on the Gigabyte (Jmicron) controller)
Adaptec 4 port SATAII in the second PCI-e slot running 4x and this holds the boot drives 4 x 500 GB Seagates in RAID 10
Adaptec 6 port SATAII in a PCI slot running a further 6 hard drives
So my PSU is running 16 hard drives (~5845.1 formatted GB of space), as well as other standard and it doesn't miss a beat.
So this post is just to say Thank you Corsair, and perhaps ask whether I need to think about a more powerful PSU. The 620 is quiet even with everything on and the PC runs 24/7 at 100% on all cores (alien hunting!).